Custom schema link in Adobe Acrobat Pro DC

Hello, I have a PDF with a custom-schema link:

This custom schema (normacs) is set in registry to launch a corresponding application (myapp.exe) to handle the link:

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\normacs\shell\open\command="C:\myapp.exe" %1

Also, the schema was appended to a list of protocols a PDF can use to access external content : 
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Policies\Adobe\Acrobat Reader\DC\FeatureLockDown\cDefaultLaunchURLPerms]
"tSchemePerms"="version:2|...|vbscript:3|normacs:2"  (for Adobe Acrobat Reader DC)

 and

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Policies\Adobe\Adobe Acrobat\DC\FeatureLockDown\cDefaultLaunchURLPerms]
"tSchemePerms"="version:2|...|vbscript:3|normacs:2"  (for Adobe Acrobat Pro DC)

Now about my problem.
When I click the link in Acrobat Reader DC, myapp.exe is launched as expected. But when I click the link in  Acrobat Pro DC (2018.11.20038), an internet browser with an empty window is opened instead of myapp.exe. 
Please suggest how to fix this. Thanks for your attention.